From 3e287e01700f48959fcd19f7e8b2de6a16d83726 Mon Sep 17 00:00:00 2001
From: Bryan Boreham <bjboreham@gmail.com>
Date: Mon, 16 Oct 2023 13:47:10 +0000
Subject: [PATCH] Scraping tests: refactor scrapeLoop creation

Pull boilerplate code into a function. Where appropriate we set some
config on the returned object.

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
---
 scrape/scrape_test.go | 818 ++++++------------------------------------
 1 file changed, 100 insertions(+), 718 deletions(-)

diff --git a/scrape/scrape_test.go b/scrape/scrape_test.go
index 5e4f3f30c..15be3bcfa 100644
--- a/scrape/scrape_test.go
+++ b/scrape/scrape_test.go
@@ -640,22 +640,22 @@ func TestScrapePoolScrapeLoopsStarted(t *testing.T) {
 	}
 }
 
-func TestScrapeLoopStopBeforeRun(t *testing.T) {
-	scraper := &testScraper{}
-
-	sl := newScrapeLoop(context.Background(),
+func newBasicScrapeLoop(t testing.TB, ctx context.Context, scraper scraper, app func(ctx context.Context) storage.Appender, interval time.Duration) *scrapeLoop {
+	return newScrapeLoop(ctx,
 		scraper,
 		nil, nil,
 		nopMutator,
 		nopMutator,
-		nil, nil, 0,
+		app,
+		nil,
+		0,
 		true,
 		false,
 		true,
 		0, 0,
 		nil,
-		1,
-		0,
+		interval,
+		time.Hour,
 		false,
 		false,
 		false,
@@ -663,6 +663,11 @@ func TestScrapeLoopStopBeforeRun(t *testing.T) {
 		false,
 		newTestScrapeMetrics(t),
 	)
+}
+
+func TestScrapeLoopStopBeforeRun(t *testing.T) {
+	scraper := &testScraper{}
+	sl := newBasicScrapeLoop(t, context.Background(), scraper, nil, 1)
 
 	// The scrape pool synchronizes on stopping scrape loops. However, new scrape
 	// loops are started asynchronously. Thus it's possible, that a loop is stopped
@@ -717,28 +722,7 @@ func TestScrapeLoopStop(t *testing.T) {
 		app      = func(ctx context.Context) storage.Appender { return appender }
 	)
 
-	sl := newScrapeLoop(context.Background(),
-		scraper,
-		nil, nil,
-		nopMutator,
-		nopMutator,
-		app,
-		nil,
-		0,
-		true,
-		false,
-		true,
-		0, 0,
-		nil,
-		10*time.Millisecond,
-		time.Hour,
-		false,
-		false,
-		false,
-		nil,
-		false,
-		newTestScrapeMetrics(t),
-	)
+	sl := newBasicScrapeLoop(t, context.Background(), scraper, app, 10*time.Millisecond)
 
 	// Terminate loop after 2 scrapes.
 	numScrapes := 0
@@ -857,28 +841,8 @@ func TestScrapeLoopRun(t *testing.T) {
 	}
 
 	ctx, cancel = context.WithCancel(context.Background())
-	sl = newScrapeLoop(ctx,
-		scraper,
-		nil, nil,
-		nopMutator,
-		nopMutator,
-		app,
-		nil,
-		0,
-		true,
-		false,
-		true,
-		0, 0,
-		nil,
-		time.Second,
-		100*time.Millisecond,
-		false,
-		false,
-		false,
-		nil,
-		false,
-		scrapeMetrics,
-	)
+	sl = newBasicScrapeLoop(t, ctx, scraper, app, time.Second)
+	sl.timeout = 100 * time.Millisecond
 
 	go func() {
 		sl.run(errc)
@@ -920,28 +884,7 @@ func TestScrapeLoopForcedErr(t *testing.T) {
 	)
 
 	ctx, cancel := context.WithCancel(context.Background())
-	sl := newScrapeLoop(ctx,
-		scraper,
-		nil, nil,
-		nopMutator,
-		nopMutator,
-		app,
-		nil,
-		0,
-		true,
-		false,
-		true,
-		0, 0,
-		nil,
-		time.Second,
-		time.Hour,
-		false,
-		false,
-		false,
-		nil,
-		false,
-		newTestScrapeMetrics(t),
-	)
+	sl := newBasicScrapeLoop(t, ctx, scraper, app, time.Second)
 
 	forcedErr := fmt.Errorf("forced err")
 	sl.setForcedError(forcedErr)
@@ -1044,28 +987,7 @@ func simpleTestScrapeLoop(t testing.TB) (context.Context, *scrapeLoop) {
 	t.Cleanup(func() { s.Close() })
 
 	ctx, cancel := context.WithCancel(context.Background())
-	sl := newScrapeLoop(ctx,
-		&testScraper{},
-		nil, nil,
-		nopMutator,
-		nopMutator,
-		s.Appender,
-		nil,
-		0,
-		true,
-		false,
-		true,
-		0, 0,
-		nil,
-		0,
-		0,
-		false,
-		false,
-		false,
-		nil,
-		false,
-		newTestScrapeMetrics(t),
-	)
+	sl := newBasicScrapeLoop(t, ctx, &testScraper{}, s.Appender, 0)
 	t.Cleanup(func() { cancel() })
 
 	return ctx, sl
@@ -1106,30 +1028,10 @@ func TestScrapeLoopFailWithInvalidLabelsAfterRelabel(t *testing.T) {
 		Separator:   ";",
 		Replacement: "$1",
 	}}
-	sl := newScrapeLoop(ctx,
-		&testScraper{},
-		nil, nil,
-		func(l labels.Labels) labels.Labels {
-			return mutateSampleLabels(l, target, true, relabelConfig)
-		},
-		nopMutator,
-		s.Appender,
-		nil,
-		0,
-		true,
-		false,
-		true,
-		0, 0,
-		nil,
-		0,
-		0,
-		false,
-		false,
-		false,
-		nil,
-		false,
-		newTestScrapeMetrics(t),
-	)
+	sl := newBasicScrapeLoop(t, ctx, &testScraper{}, s.Appender, 0)
+	sl.sampleMutator = func(l labels.Labels) labels.Labels {
+		return mutateSampleLabels(l, target, true, relabelConfig)
+	}
 
 	slApp := sl.appender(ctx)
 	total, added, seriesAdded, err := sl.append(slApp, []byte("test_metric 1\n"), "", time.Time{})
@@ -1190,28 +1092,7 @@ func TestScrapeLoopRunCreatesStaleMarkersOnFailedScrape(t *testing.T) {
 	)
 
 	ctx, cancel := context.WithCancel(context.Background())
-	sl := newScrapeLoop(ctx,
-		scraper,
-		nil, nil,
-		nopMutator,
-		nopMutator,
-		app,
-		nil,
-		0,
-		true,
-		false,
-		true,
-		0, 0,
-		nil,
-		10*time.Millisecond,
-		time.Hour,
-		false,
-		false,
-		false,
-		nil,
-		false,
-		newTestScrapeMetrics(t),
-	)
+	sl := newBasicScrapeLoop(t, ctx, scraper, app, 10*time.Millisecond)
 	// Succeed once, several failures, then stop.
 	numScrapes := 0
 
@@ -1257,28 +1138,7 @@ func TestScrapeLoopRunCreatesStaleMarkersOnParseFailure(t *testing.T) {
 	)
 
 	ctx, cancel := context.WithCancel(context.Background())
-	sl := newScrapeLoop(ctx,
-		scraper,
-		nil, nil,
-		nopMutator,
-		nopMutator,
-		app,
-		nil,
-		0,
-		true,
-		false,
-		true,
-		0, 0,
-		nil,
-		10*time.Millisecond,
-		time.Hour,
-		false,
-		false,
-		false,
-		nil,
-		false,
-		newTestScrapeMetrics(t),
-	)
+	sl := newBasicScrapeLoop(t, ctx, scraper, app, 10*time.Millisecond)
 
 	// Succeed once, several failures, then stop.
 	scraper.scrapeFunc = func(ctx context.Context, w io.Writer) error {
@@ -1327,28 +1187,7 @@ func TestScrapeLoopCache(t *testing.T) {
 	)
 
 	ctx, cancel := context.WithCancel(context.Background())
-	sl := newScrapeLoop(ctx,
-		scraper,
-		nil, nil,
-		nopMutator,
-		nopMutator,
-		app,
-		nil,
-		0,
-		true,
-		false,
-		true,
-		0, 0,
-		nil,
-		10*time.Millisecond,
-		time.Hour,
-		false,
-		false,
-		false,
-		nil,
-		false,
-		newTestScrapeMetrics(t),
-	)
+	sl := newBasicScrapeLoop(t, ctx, scraper, app, 10*time.Millisecond)
 
 	numScrapes := 0
 
@@ -1414,28 +1253,7 @@ func TestScrapeLoopCacheMemoryExhaustionProtection(t *testing.T) {
 	)
 
 	ctx, cancel := context.WithCancel(context.Background())
-	sl := newScrapeLoop(ctx,
-		scraper,
-		nil, nil,
-		nopMutator,
-		nopMutator,
-		app,
-		nil,
-		0,
-		true,
-		false,
-		true,
-		0, 0,
-		nil,
-		10*time.Millisecond,
-		time.Hour,
-		false,
-		false,
-		false,
-		nil,
-		false,
-		newTestScrapeMetrics(t),
-	)
+	sl := newBasicScrapeLoop(t, ctx, scraper, app, 10*time.Millisecond)
 
 	numScrapes := 0
 
@@ -1529,31 +1347,13 @@ func TestScrapeLoopAppend(t *testing.T) {
 			labels: labels.FromStrings(test.discoveryLabels...),
 		}
 
-		sl := newScrapeLoop(context.Background(),
-			nil, nil, nil,
-			func(l labels.Labels) labels.Labels {
-				return mutateSampleLabels(l, discoveryLabels, test.honorLabels, nil)
-			},
-			func(l labels.Labels) labels.Labels {
-				return mutateReportSampleLabels(l, discoveryLabels)
-			},
-			func(ctx context.Context) storage.Appender { return app },
-			nil,
-			0,
-			true,
-			false,
-			true,
-			0, 0,
-			nil,
-			0,
-			0,
-			false,
-			false,
-			false,
-			nil,
-			false,
-			newTestScrapeMetrics(t),
-		)
+		sl := newBasicScrapeLoop(t, context.Background(), nil, func(ctx context.Context) storage.Appender { return app }, 0)
+		sl.sampleMutator = func(l labels.Labels) labels.Labels {
+			return mutateSampleLabels(l, discoveryLabels, test.honorLabels, nil)
+		}
+		sl.reportSampleMutator = func(l labels.Labels) labels.Labels {
+			return mutateReportSampleLabels(l, discoveryLabels)
+		}
 
 		now := time.Now()
 
@@ -1635,14 +1435,10 @@ func TestScrapeLoopAppendForConflictingPrefixedLabels(t *testing.T) {
 	for name, tc := range testcases {
 		t.Run(name, func(t *testing.T) {
 			app := &collectResultAppender{}
-			sl := newScrapeLoop(context.Background(), nil, nil, nil,
-				func(l labels.Labels) labels.Labels {
-					return mutateSampleLabels(l, &Target{labels: labels.FromStrings(tc.targetLabels...)}, false, nil)
-				},
-				nil,
-				func(ctx context.Context) storage.Appender { return app },
-				nil, 0, true, false, true, 0, 0, nil, 0, 0, false, false, false, nil, false, newTestScrapeMetrics(t),
-			)
+			sl := newBasicScrapeLoop(t, context.Background(), nil, func(ctx context.Context) storage.Appender { return app }, 0)
+			sl.sampleMutator = func(l labels.Labels) labels.Labels {
+				return mutateSampleLabels(l, &Target{labels: labels.FromStrings(tc.targetLabels...)}, false, nil)
+			}
 			slApp := sl.appender(context.Background())
 			_, _, _, err := sl.append(slApp, []byte(tc.exposedLabels), "", time.Date(2000, 1, 1, 1, 0, 0, 0, time.UTC))
 			require.NoError(t, err)
@@ -1663,28 +1459,7 @@ func TestScrapeLoopAppendForConflictingPrefixedLabels(t *testing.T) {
 func TestScrapeLoopAppendCacheEntryButErrNotFound(t *testing.T) {
 	// collectResultAppender's AddFast always returns ErrNotFound if we don't give it a next.
 	app := &collectResultAppender{}
-
-	sl := newScrapeLoop(context.Background(),
-		nil, nil, nil,
-		nopMutator,
-		nopMutator,
-		func(ctx context.Context) storage.Appender { return app },
-		nil,
-		0,
-		true,
-		false,
-		true,
-		0, 0,
-		nil,
-		0,
-		0,
-		false,
-		false,
-		false,
-		nil,
-		false,
-		newTestScrapeMetrics(t),
-	)
+	sl := newBasicScrapeLoop(t, context.Background(), nil, func(ctx context.Context) storage.Appender { return app }, 0)
 
 	fakeRef := storage.SeriesRef(1)
 	expValue := float64(1)
@@ -1721,32 +1496,14 @@ func TestScrapeLoopAppendSampleLimit(t *testing.T) {
 	resApp := &collectResultAppender{}
 	app := &limitAppender{Appender: resApp, limit: 1}
 
-	sl := newScrapeLoop(context.Background(),
-		nil, nil, nil,
-		func(l labels.Labels) labels.Labels {
-			if l.Has("deleteme") {
-				return labels.EmptyLabels()
-			}
-			return l
-		},
-		nopMutator,
-		func(ctx context.Context) storage.Appender { return app },
-		nil,
-		0,
-		true,
-		false,
-		true,
-		app.limit, 0,
-		nil,
-		0,
-		0,
-		false,
-		false,
-		false,
-		nil,
-		false,
-		newTestScrapeMetrics(t),
-	)
+	sl := newBasicScrapeLoop(t, context.Background(), nil, func(ctx context.Context) storage.Appender { return app }, 0)
+	sl.sampleMutator = func(l labels.Labels) labels.Labels {
+		if l.Has("deleteme") {
+			return labels.EmptyLabels()
+		}
+		return l
+	}
+	sl.sampleLimit = app.limit
 
 	// Get the value of the Counter before performing the append.
 	beforeMetric := dto.Metric{}
@@ -1802,32 +1559,14 @@ func TestScrapeLoop_HistogramBucketLimit(t *testing.T) {
 	resApp := &collectResultAppender{}
 	app := &bucketLimitAppender{Appender: resApp, limit: 2}
 
-	sl := newScrapeLoop(context.Background(),
-		nil, nil, nil,
-		func(l labels.Labels) labels.Labels {
-			if l.Has("deleteme") {
-				return labels.EmptyLabels()
-			}
-			return l
-		},
-		nopMutator,
-		func(ctx context.Context) storage.Appender { return app },
-		nil,
-		0,
-		true,
-		false,
-		true,
-		app.limit, 0,
-		nil,
-		0,
-		0,
-		false,
-		false,
-		false,
-		nil,
-		false,
-		newTestScrapeMetrics(t),
-	)
+	sl := newBasicScrapeLoop(t, context.Background(), nil, func(ctx context.Context) storage.Appender { return app }, 0)
+	sl.sampleMutator = func(l labels.Labels) labels.Labels {
+		if l.Has("deleteme") {
+			return labels.EmptyLabels()
+		}
+		return l
+	}
+	sl.sampleLimit = app.limit
 
 	metric := dto.Metric{}
 	err := sl.metrics.targetScrapeNativeHistogramBucketLimit.Write(&metric)
@@ -1908,28 +1647,7 @@ func TestScrapeLoop_ChangingMetricString(t *testing.T) {
 	defer s.Close()
 
 	capp := &collectResultAppender{}
-
-	sl := newScrapeLoop(context.Background(),
-		nil, nil, nil,
-		nopMutator,
-		nopMutator,
-		func(ctx context.Context) storage.Appender { capp.next = s.Appender(ctx); return capp },
-		nil,
-		0,
-		true,
-		false,
-		true,
-		0, 0,
-		nil,
-		0,
-		0,
-		false,
-		false,
-		false,
-		nil,
-		false,
-		newTestScrapeMetrics(t),
-	)
+	sl := newBasicScrapeLoop(t, context.Background(), nil, func(ctx context.Context) storage.Appender { return capp }, 0)
 
 	now := time.Now()
 	slApp := sl.appender(context.Background())
@@ -1961,27 +1679,7 @@ func TestScrapeLoop_ChangingMetricString(t *testing.T) {
 func TestScrapeLoopAppendStaleness(t *testing.T) {
 	app := &collectResultAppender{}
 
-	sl := newScrapeLoop(context.Background(),
-		nil, nil, nil,
-		nopMutator,
-		nopMutator,
-		func(ctx context.Context) storage.Appender { return app },
-		nil,
-		0,
-		true,
-		false,
-		true,
-		0, 0,
-		nil,
-		0,
-		0,
-		false,
-		false,
-		false,
-		nil,
-		false,
-		newTestScrapeMetrics(t),
-	)
+	sl := newBasicScrapeLoop(t, context.Background(), nil, func(ctx context.Context) storage.Appender { return app }, 0)
 
 	now := time.Now()
 	slApp := sl.appender(context.Background())
@@ -2016,28 +1714,7 @@ func TestScrapeLoopAppendStaleness(t *testing.T) {
 
 func TestScrapeLoopAppendNoStalenessIfTimestamp(t *testing.T) {
 	app := &collectResultAppender{}
-	sl := newScrapeLoop(context.Background(),
-		nil, nil, nil,
-		nopMutator,
-		nopMutator,
-		func(ctx context.Context) storage.Appender { return app },
-		nil,
-		0,
-		true,
-		false,
-		true,
-		0, 0,
-		nil,
-		0,
-		0,
-		false,
-		false,
-		false,
-		nil,
-		false,
-		newTestScrapeMetrics(t),
-	)
-
+	sl := newBasicScrapeLoop(t, context.Background(), nil, func(ctx context.Context) storage.Appender { return app }, 0)
 	now := time.Now()
 	slApp := sl.appender(context.Background())
 	_, _, _, err := sl.append(slApp, []byte("metric_a 1 1000\n"), "", now)
@@ -2061,27 +1738,8 @@ func TestScrapeLoopAppendNoStalenessIfTimestamp(t *testing.T) {
 
 func TestScrapeLoopAppendStalenessIfTrackTimestampStaleness(t *testing.T) {
 	app := &collectResultAppender{}
-	sl := newScrapeLoop(context.Background(),
-		nil, nil, nil,
-		nopMutator,
-		nopMutator,
-		func(ctx context.Context) storage.Appender { return app },
-		nil,
-		0,
-		true,
-		true,
-		true,
-		0, 0,
-		nil,
-		0,
-		0,
-		false,
-		false,
-		false,
-		nil,
-		false,
-		newTestScrapeMetrics(t),
-	)
+	sl := newBasicScrapeLoop(t, context.Background(), nil, func(ctx context.Context) storage.Appender { return app }, 0)
+	sl.trackTimestampsStaleness = true
 
 	now := time.Now()
 	slApp := sl.appender(context.Background())
@@ -2430,31 +2088,14 @@ metric: <
 				labels: labels.FromStrings(test.discoveryLabels...),
 			}
 
-			sl := newScrapeLoop(context.Background(),
-				nil, nil, nil,
-				func(l labels.Labels) labels.Labels {
-					return mutateSampleLabels(l, discoveryLabels, false, nil)
-				},
-				func(l labels.Labels) labels.Labels {
-					return mutateReportSampleLabels(l, discoveryLabels)
-				},
-				func(ctx context.Context) storage.Appender { return app },
-				nil,
-				0,
-				true,
-				false,
-				true,
-				0, 0,
-				nil,
-				0,
-				0,
-				test.scrapeClassicHistograms,
-				false,
-				false,
-				nil,
-				false,
-				newTestScrapeMetrics(t),
-			)
+			sl := newBasicScrapeLoop(t, context.Background(), nil, func(ctx context.Context) storage.Appender { return app }, 0)
+			sl.sampleMutator = func(l labels.Labels) labels.Labels {
+				return mutateSampleLabels(l, discoveryLabels, false, nil)
+			}
+			sl.reportSampleMutator = func(l labels.Labels) labels.Labels {
+				return mutateReportSampleLabels(l, discoveryLabels)
+			}
+			sl.scrapeClassicHistograms = test.scrapeClassicHistograms
 
 			now := time.Now()
 
@@ -2521,31 +2162,13 @@ func TestScrapeLoopAppendExemplarSeries(t *testing.T) {
 
 	app := &collectResultAppender{}
 
-	sl := newScrapeLoop(context.Background(),
-		nil, nil, nil,
-		func(l labels.Labels) labels.Labels {
-			return mutateSampleLabels(l, discoveryLabels, false, nil)
-		},
-		func(l labels.Labels) labels.Labels {
-			return mutateReportSampleLabels(l, discoveryLabels)
-		},
-		func(ctx context.Context) storage.Appender { return app },
-		nil,
-		0,
-		true,
-		false,
-		true,
-		0, 0,
-		nil,
-		0,
-		0,
-		false,
-		false,
-		false,
-		nil,
-		false,
-		newTestScrapeMetrics(t),
-	)
+	sl := newBasicScrapeLoop(t, context.Background(), nil, func(ctx context.Context) storage.Appender { return app }, 0)
+	sl.sampleMutator = func(l labels.Labels) labels.Labels {
+		return mutateSampleLabels(l, discoveryLabels, false, nil)
+	}
+	sl.reportSampleMutator = func(l labels.Labels) labels.Labels {
+		return mutateReportSampleLabels(l, discoveryLabels)
+	}
 
 	now := time.Now()
 
@@ -2580,28 +2203,7 @@ func TestScrapeLoopRunReportsTargetDownOnScrapeError(t *testing.T) {
 	)
 
 	ctx, cancel := context.WithCancel(context.Background())
-	sl := newScrapeLoop(ctx,
-		scraper,
-		nil, nil,
-		nopMutator,
-		nopMutator,
-		app,
-		nil,
-		0,
-		true,
-		false,
-		true,
-		0, 0,
-		nil,
-		10*time.Millisecond,
-		time.Hour,
-		false,
-		false,
-		false,
-		nil,
-		false,
-		newTestScrapeMetrics(t),
-	)
+	sl := newBasicScrapeLoop(t, ctx, scraper, app, 10*time.Millisecond)
 
 	scraper.scrapeFunc = func(ctx context.Context, w io.Writer) error {
 		cancel()
@@ -2620,28 +2222,7 @@ func TestScrapeLoopRunReportsTargetDownOnInvalidUTF8(t *testing.T) {
 	)
 
 	ctx, cancel := context.WithCancel(context.Background())
-	sl := newScrapeLoop(ctx,
-		scraper,
-		nil, nil,
-		nopMutator,
-		nopMutator,
-		app,
-		nil,
-		0,
-		true,
-		false,
-		true,
-		0, 0,
-		nil,
-		10*time.Millisecond,
-		time.Hour,
-		false,
-		false,
-		false,
-		nil,
-		false,
-		newTestScrapeMetrics(t),
-	)
+	sl := newBasicScrapeLoop(t, ctx, scraper, app, 10*time.Millisecond)
 
 	scraper.scrapeFunc = func(ctx context.Context, w io.Writer) error {
 		cancel()
@@ -2672,29 +2253,7 @@ func (app *errorAppender) Append(ref storage.SeriesRef, lset labels.Labels, t in
 
 func TestScrapeLoopAppendGracefullyIfAmendOrOutOfOrderOrOutOfBounds(t *testing.T) {
 	app := &errorAppender{}
-
-	sl := newScrapeLoop(context.Background(),
-		nil,
-		nil, nil,
-		nopMutator,
-		nopMutator,
-		func(ctx context.Context) storage.Appender { return app },
-		nil,
-		0,
-		true,
-		false,
-		true,
-		0, 0,
-		nil,
-		0,
-		0,
-		false,
-		false,
-		false,
-		nil,
-		false,
-		newTestScrapeMetrics(t),
-	)
+	sl := newBasicScrapeLoop(t, context.Background(), nil, func(ctx context.Context) storage.Appender { return app }, 0)
 
 	now := time.Unix(1, 0)
 	slApp := sl.appender(context.Background())
@@ -2717,32 +2276,14 @@ func TestScrapeLoopAppendGracefullyIfAmendOrOutOfOrderOrOutOfBounds(t *testing.T
 
 func TestScrapeLoopOutOfBoundsTimeError(t *testing.T) {
 	app := &collectResultAppender{}
-	sl := newScrapeLoop(context.Background(),
-		nil,
-		nil, nil,
-		nopMutator,
-		nopMutator,
+	sl := newBasicScrapeLoop(t, context.Background(), nil,
 		func(ctx context.Context) storage.Appender {
 			return &timeLimitAppender{
 				Appender: app,
 				maxTime:  timestamp.FromTime(time.Now().Add(10 * time.Minute)),
 			}
 		},
-		nil,
 		0,
-		true,
-		false,
-		true,
-		0, 0,
-		nil,
-		0,
-		0,
-		false,
-		false,
-		false,
-		nil,
-		false,
-		newTestScrapeMetrics(t),
 	)
 
 	now := time.Now().Add(20 * time.Minute)
@@ -3014,29 +2555,8 @@ func TestScrapeLoop_RespectTimestamps(t *testing.T) {
 	defer s.Close()
 
 	app := s.Appender(context.Background())
-
 	capp := &collectResultAppender{next: app}
-
-	sl := newScrapeLoop(context.Background(),
-		nil, nil, nil,
-		nopMutator,
-		nopMutator,
-		func(ctx context.Context) storage.Appender { return capp },
-		nil, 0,
-		true,
-		false,
-		true,
-		0, 0,
-		nil,
-		0,
-		0,
-		false,
-		false,
-		false,
-		nil,
-		false,
-		newTestScrapeMetrics(t),
-	)
+	sl := newBasicScrapeLoop(t, context.Background(), nil, func(ctx context.Context) storage.Appender { return capp }, 0)
 
 	now := time.Now()
 	slApp := sl.appender(context.Background())
@@ -3062,26 +2582,8 @@ func TestScrapeLoop_DiscardTimestamps(t *testing.T) {
 
 	capp := &collectResultAppender{next: app}
 
-	sl := newScrapeLoop(context.Background(),
-		nil, nil, nil,
-		nopMutator,
-		nopMutator,
-		func(ctx context.Context) storage.Appender { return capp },
-		nil, 0,
-		false,
-		false,
-		true,
-		0, 0,
-		nil,
-		0,
-		0,
-		false,
-		false,
-		false,
-		nil,
-		false,
-		newTestScrapeMetrics(t),
-	)
+	sl := newBasicScrapeLoop(t, context.Background(), nil, func(ctx context.Context) storage.Appender { return capp }, 0)
+	sl.honorTimestamps = false
 
 	now := time.Now()
 	slApp := sl.appender(context.Background())
@@ -3104,28 +2606,7 @@ func TestScrapeLoopDiscardDuplicateLabels(t *testing.T) {
 	defer s.Close()
 
 	ctx, cancel := context.WithCancel(context.Background())
-	sl := newScrapeLoop(ctx,
-		&testScraper{},
-		nil, nil,
-		nopMutator,
-		nopMutator,
-		s.Appender,
-		nil,
-		0,
-		true,
-		false,
-		true,
-		0, 0,
-		nil,
-		0,
-		0,
-		false,
-		false,
-		false,
-		nil,
-		false,
-		newTestScrapeMetrics(t),
-	)
+	sl := newBasicScrapeLoop(t, ctx, &testScraper{}, s.Appender, 0)
 	defer cancel()
 
 	// We add a good and a bad metric to check that both are discarded.
@@ -3161,33 +2642,13 @@ func TestScrapeLoopDiscardUnnamedMetrics(t *testing.T) {
 	app := s.Appender(context.Background())
 
 	ctx, cancel := context.WithCancel(context.Background())
-	sl := newScrapeLoop(context.Background(),
-		&testScraper{},
-		nil, nil,
-		func(l labels.Labels) labels.Labels {
-			if l.Has("drop") {
-				return labels.FromStrings("no", "name") // This label set will trigger an error.
-			}
-			return l
-		},
-		nopMutator,
-		func(ctx context.Context) storage.Appender { return app },
-		nil,
-		0,
-		true,
-		false,
-		true,
-		0, 0,
-		nil,
-		0,
-		0,
-		false,
-		false,
-		false,
-		nil,
-		false,
-		newTestScrapeMetrics(t),
-	)
+	sl := newBasicScrapeLoop(t, context.Background(), &testScraper{}, func(ctx context.Context) storage.Appender { return app }, 0)
+	sl.sampleMutator = func(l labels.Labels) labels.Labels {
+		if l.Has("drop") {
+			return labels.FromStrings("no", "name") // This label set will trigger an error.
+		}
+		return l
+	}
 	defer cancel()
 
 	slApp := sl.appender(context.Background())
@@ -3433,28 +2894,7 @@ func TestScrapeAddFast(t *testing.T) {
 	defer s.Close()
 
 	ctx, cancel := context.WithCancel(context.Background())
-	sl := newScrapeLoop(ctx,
-		&testScraper{},
-		nil, nil,
-		nopMutator,
-		nopMutator,
-		s.Appender,
-		nil,
-		0,
-		true,
-		false,
-		true,
-		0, 0,
-		nil,
-		0,
-		0,
-		false,
-		false,
-		false,
-		nil,
-		false,
-		newTestScrapeMetrics(t),
-	)
+	sl := newBasicScrapeLoop(t, ctx, &testScraper{}, s.Appender, 0)
 	defer cancel()
 
 	slApp := sl.appender(ctx)
@@ -3523,28 +2963,7 @@ func TestScrapeReportSingleAppender(t *testing.T) {
 	)
 
 	ctx, cancel := context.WithCancel(context.Background())
-	sl := newScrapeLoop(ctx,
-		scraper,
-		nil, nil,
-		nopMutator,
-		nopMutator,
-		s.Appender,
-		nil,
-		0,
-		true,
-		false,
-		true,
-		0, 0,
-		nil,
-		10*time.Millisecond,
-		time.Hour,
-		false,
-		false,
-		false,
-		nil,
-		false,
-		newTestScrapeMetrics(t),
-	)
+	sl := newBasicScrapeLoop(t, ctx, scraper, s.Appender, 10*time.Millisecond)
 
 	numScrapes := 0
 
@@ -3726,31 +3145,14 @@ func TestScrapeLoopLabelLimit(t *testing.T) {
 			labels: labels.FromStrings(test.discoveryLabels...),
 		}
 
-		sl := newScrapeLoop(context.Background(),
-			nil, nil, nil,
-			func(l labels.Labels) labels.Labels {
-				return mutateSampleLabels(l, discoveryLabels, false, nil)
-			},
-			func(l labels.Labels) labels.Labels {
-				return mutateReportSampleLabels(l, discoveryLabels)
-			},
-			func(ctx context.Context) storage.Appender { return app },
-			nil,
-			0,
-			true,
-			false,
-			true,
-			0, 0,
-			&test.labelLimits,
-			0,
-			0,
-			false,
-			false,
-			false,
-			nil,
-			false,
-			newTestScrapeMetrics(t),
-		)
+		sl := newBasicScrapeLoop(t, context.Background(), nil, func(ctx context.Context) storage.Appender { return app }, 0)
+		sl.sampleMutator = func(l labels.Labels) labels.Labels {
+			return mutateSampleLabels(l, discoveryLabels, false, nil)
+		}
+		sl.reportSampleMutator = func(l labels.Labels) labels.Labels {
+			return mutateReportSampleLabels(l, discoveryLabels)
+		}
+		sl.labelLimits = &test.labelLimits
 
 		slApp := sl.appender(context.Background())
 		_, _, _, err := sl.append(slApp, []byte(test.scrapeLabels), "", time.Now())
@@ -3936,28 +3338,8 @@ func TestScrapeLoopRunCreatesStaleMarkersOnFailedScrapeForTimestampedMetrics(t *
 	)
 
 	ctx, cancel := context.WithCancel(context.Background())
-	sl := newScrapeLoop(ctx,
-		scraper,
-		nil, nil,
-		nopMutator,
-		nopMutator,
-		app,
-		nil,
-		0,
-		true,
-		true,
-		true,
-		0, 0,
-		nil,
-		10*time.Millisecond,
-		time.Hour,
-		false,
-		false,
-		false,
-		nil,
-		false,
-		newTestScrapeMetrics(t),
-	)
+	sl := newBasicScrapeLoop(t, ctx, scraper, app, 10*time.Millisecond)
+	sl.trackTimestampsStaleness = true
 	// Succeed once, several failures, then stop.
 	numScrapes := 0